Filter delivery system

ABSTRACT

A filter delivery device for implanting a vessel filter within a blood vessel of a patient&#39;s body. The filter delivery device includes a mechanism for preventing hooks and/or legs on a vessel filter from entangling with each other while the vessel filter is loaded within the delivery device. In one variation, the filter delivery device includes a delivery catheter with grooves at the distal end lumen opening. When a vessel filter with radially expanding legs is compressed and inserted into the distal end of the delivery catheter, the hooks on the distal end of the legs are received and separated by the corresponding grooves on the delivery catheter. In another variation, a pusher rod, with a receptacle for receiving the hooks, is positioned within a delivery catheter to prevent the entanglement of the hooks and/or legs of a filter loaded within the delivery catheter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 10/986,714,filed 12 Nov. 2004, now U.S. Pat. No. 7,794,473, and U.S. patent Ser.No. 12/880,839, filed Sep. 13, 2010, now U.S. patent Ser. No.8,992,562,which is incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable

REFERENCE TO A “MICROFICHE APPENDIX”

Not applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vessel filters and vessel deliverysystems. More particularly, the present invention relates to an improvedvessel filter and delivery system having a delivery catheter of improvedconfiguration that accepts a filter in a folded condition wherein thefilter has specially configured appendages with outwardly directed hooksthat engage indentations or recesses in the catheter wall.

2. General Background of the Invention

A vessel filter is a device inserted into a blood vessel to captureparticles in the blood flow. Typically the device is inserted into amajor vein to prevent a blood clot from reaching the lungs. Patients,who have recently suffered from trauma, have experienced a heart attack(myocardial infarction), or who have undergone major surgical procedure(e.g., surgical repair of a fractured hip, etc.) may have thrombosis ina deep vein. When the thrombus clot loosens from the site of formationand travels to the lung it may cause pulmonary embolism, alife-threatening condition. A vessel filter may be placed in thecirculatory system to intercept the thrombi and prevent them fromentering the lungs.

Examples of various blood vessel filters and delivery systems aredisclosed in the following table:

TABLE PAT. NO. TITLE ISSUE DATE 2001/0000799 A1 “BODY VESSEL FILTER” May3, 2001 2002/0038097 A1 “ATRAUMATIC ANCHORING AND Sep. 26, 2002DISENGAGEMENT MECHANISM FOR PERMANENT IMPLANT DEVICE” 2002/0193828 A1“ENDOVASCULAR FILTER” Dec. 19, 2002 2003/0199918 A1 “CONVERTIBLE BLOODCLOT FILTER” Oct. 23, 2003 2003/0208227 A1 “TEMPORARY VASCULAR FILTERSNov. 6, 2003 AND METHODS” 2003/0208253 A1 “BLOOD CLOT FILTER” Nov. 6,2003 2004/0082966 A1 “STAGED RELEASE OF IVC FILTER LEGS Apr. 29, 20044,425,908 “BLOOD CLOT FILTER” Jan. 17, 1984; 4,643,184 “EMBOLUS TRAP”Feb. 17, 1987; 4,817,600 “IMPLANTABLE FILTER” Apr. 4, 1989; 5,059,205“PERCUTANEOUS ANTI-MIGRATION Oct. 22, 1991; VENA CAVA FILTER” 5,147,379“INSERTION INSTRUMENT FOR Sep. 15, 1992; VENA CAVA FILTER” 5,626,605“THROMBOSIS FILTER” May 6, 1997; 5,634,942 “ASSEMBLY COMPRISING A BLOODJun. 3, 1997; FILTER FOR TEMPORARY OR DEFINITIVE USE AND A DEVICE FORIMPLANTING IT” 5,755,790 “INTRALUMINAL MEDICAL DEVICE” May 26, 1998;5,853,420 “ASSEMBLY COMPRISING A BLOOD Dec. 29, 1998; FILTER FORTEMPORARY OR DEFINITIVE USE AND A DEVICE FOR IMPLANTING IT,CORRESPONDING FILTER AND METHOD OF IMPLANTING SUCH A FILTER” 6,258,026B1 “REMOVABLE EMBOLUS BLOOD CLOT Jul. 10, 2001; FILTER AND FILTERDELIVERY UNIT” 6,342,062 B1 “RETRIEVAL DEVICES FOR VENA Jan. 29, 2002;CAVA FILTER” 6,383,193 B1 “VENA CAVA DELIVERY SYSTEM” May 7, 2002;6,497,709 B1 “METAL MEDICAL DEVICE” Dec. 24, 2002; 6,506,205 B2 “BLOODCLOT FILTERING SYSTEM Jan. 14, 2003; 6,517,559 B1 “BLOOD FILTER ANDMETHOD FOR Feb. 11, 2003; TREATING VASCULAR DISEASE” 6,540,767 B1“RECOILABLE THROMBOSIS Apr. 1, 2003; FILTERING DEVICE AND METHOD”6,620,183 B2 “THROMBUS FILTER WITH BREAK- Sep. 16, 2003; AWAY ANCHORMEMBERS”Each of above listed patents is incorporated herein by reference in itsentirety.

Typically, the filter comprises a plurality of radially expandable legsthat support one or more filter baskets having a conical configuration.The device is configured for compression into a small size to facilitatedelivery into a vascular passageway and is subsequently expandable intocontact with the inner wall of the vessel. The device may later beretrieved from the deployed site by compressing the radially expandedlegs and the associated baskets back into a small size for retrieval.The radially expandable leg may further comprise engagements foranchoring the filter in position within a blood vessel (e.g., venacava). For example, the expandable legs may have hooks that canpenetrate into the vessel wall and positively prevent migration of thefilter in either direction along the length of the vessel. The body ofthe filter may comprise various biocompatible materials includingcompressible spring metals and shape memory materials to allow easyexpansion and compression of the filter within the vessel. The hooks onthe radially expandable legs may further comprise materials more elasticthan the legs to permit the hooks to straighten in response towithdrawal forces to facilitate withdrawal from the endothelium layerwithout risk of significant injury to the vessel wall. The hooks may beformed on selected radially expandable legs, but not on others.

Many of the existing vena cava filters routinely encounter problemsduring deployment due to entanglements of the radially expandable legs.This is especially problematic in designs with hooks implemented on theradially expandable legs. In the compressed/collapsed condition, thevarious hooks on the legs may interlock with other legs or hooks andrender the device useless. Thus, an improved vessel filter deliverydevice that can prevent entanglement and/or interlocking of the radiallyexpandable legs when the filter is collapsed and placed inside thedelivery device is desirable.

BRIEF SUMMARY OF THE INVENTION

Accordingly, described herein is a vessel filter delivery device with abuilt-in mechanism for preventing the hooks on the radially expandablelegs from interlocking when the vessel filter is compressed and insertedinto the lumen of a delivery catheter. The improved vessel filterdelivery device may also prevent the radially expandable legs frombecoming entangled. In one variation, the vessel filter delivery devicecomprises an elongated catheter configured with a plurality of groovesat the distal opening to separate the hooks on a vessel filter loaded inthe lumen of the catheter. Preferably, each of the grooves has one endthat opens at the distal tip of the catheter to allow the hooks to slideout without obstruction, and the proximal end of the groove isconfigured with a ledge to prevent the catheter from migrating towardthe proximal end of the catheter, keeping the vessel filter at theproximal end of the catheter lumen. The ledge may be configured with aprofile approximating the curvature of the hook to help maintain theshape of the hook while the vessel filter is loaded inside the deliverycatheter. The profile on the ledge may also be configured to minimizefatigue of the material comprising the hook. This feature may beparticularly useful for hooks comprised of a shape memory material.Furthermore, a pusher-wire with an attachment interface at the distalend for capturing the head or the sleeve of the vessel filter may beutilized for loading and unloading the vessel filter from the catheter.

In another variation, the vessel filter delivery device is configuredwith a mechanism for centering the delivery catheter prior to deployingthe vessel filter. In one example, the delivery catheter is configuredwith a plurality of flexible elements extending from the distal end ofthe catheter and flaring outward from the longitudinal axis of thecatheter. When the delivery catheter is disposed within an introducersheath, the wall of the introducer sheath compresses the plurality ofwirings and allows the advancement of the catheter within the introducersheath. As the introducer sheath is retracted from the distal end of thedelivery catheter, the flexible elements protrude and expand from thedistal opening of the sheath, and as a result, center the distal end ofthe catheter within the blood vessel. Centering of the delivery cathetermay allow smoother deployment of the vessel filter, and also assist thelegs of the vessel filter to expand evenly and center itself within theblood vessel. The deployment catheter with a centering mechanism mayalso be configured with grooves at the distal end of the lumen toprevent the hooks and legs of the vessel filter from entanglement.

In yet another variation, the vessel filter delivery device comprises apusher-wire with an integrated receptacle for holding and separating thehooks on the legs of the vessel filter. The receptacle may preventinterlocking of the hooks and entanglement of the legs. The preloadingof the hooks into the receptacle may also facilitate the loading of thevessel filter into the lumen of the catheter. In one example, the pusherdevice comprises an elongated wire with a pusher pad attached to thedistal end thereof. An extension wiring connects a receptacle to thedistal end of the pusher pad. The receptacle may be configured with aplurality of orifices. Each orifice is configured to receive a filterhook and/or its corresponding leg.

The improved vessel filter delivery device may provide one or more ofthe various advantages listed below: improved placement of the vesselfilter in the delivery device; prevent loaded vessel filter frommigrating towards the proximal end of the delivery device; minimizationof fatigue of the vessel filter hooks while the vessel filter is loadedwithin the delivery device; improved deployability due to easier releaseof the radially expandable legs; improved deployment orientation andposition of the vessel filter, which may result in improved trapping ofsignificant emboli, good vessel patency, limited thrombogenic responseat the implantation site, and a decrease in the risk of the hooksperforating the vessel wall.

These and other embodiments, features and advantages of the presentinvention will become more apparent to those skilled in the art whentaken with reference to the following more detailed description of theinvention in conjunction with the accompanying drawings that are firstbriefly described.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a further understanding of the nature, objects, and advantages ofthe present invention, reference should be had to the following detaileddescription, read in conjunction with the following drawings, whereinlike reference numerals denote like elements and wherein:

FIG. 1 illustrates one variation of a delivery catheter comprising acatheter with grooves at the distal lumen for receiving the hooks at thedistal end of the vessel filter.

FIG. 2 illustrates one variation of a vessel filter in an expandedposition.

FIG. 3 illustrates an example of a vessel filter positioned within thedelivery catheter for deployment. The hooks on the vessel filter areresting within the grooves that are cut into the cross-sectional area atthe distal end of the delivery catheter. The delivery catheter is shownpositioned within the lumen of an introducer sheath.

FIG. 4A is the frontal view of the vessel filter delivery system shownin FIG. 3, illustrating the distribution of the vessel filter legswithin the lumen of the delivery catheter. The device is shown from thedistal end of the delivery catheter down its longitudinal axis.

FIG. 4B is a cross-sectional view illustrating a hook of a vessel filterpositioned within a groove in the delivery catheter. The catheter isshown sectioned along the length of the catheter.

FIG. 4C is a cross-sectional view of a delivery catheter illustratingone variation of a groove on the inner circumferential surface of adelivery catheter.

FIG. 4D is a sectional view illustrating the dimension of the grooves onanother variation of the delivery catheter. The catheter is shownsectioned along the length of the catheter, with a vessel filter loadedin the lumen of the catheter.

FIG. 5A is a cross-sectional view illustrating one variation of a splinecap. The spline cap is configured for attachment to the distal end of acatheter to provide the hook receiving grooves.

FIG. 5B is a frontal view of the spline cap of FIG. 5A. The spline capis shown from the distal end down its longitudinal axis.

FIG. 6A is a perspective view of another variation of a spline cap. Inthis design, the proximal portion of the spline cap is configured forinsertion into the lumen of a catheter.

FIG. 6B is a cross-sectional view of the spline cap of FIG. 6A.

FIG. 6C is a frontal view of the spline cap of FIG. 6A. The spline capis shown from the distal end down its longitudinal axis.

FIG. 6D illustrates an example of a filter delivery system with thespline cap of FIG. 6A implemented at the distal end of the deliverycatheter. A vessel filter and a pusher-wire are positioned within thelumen of the delivery catheter. The delivery catheter is slidablydisposed within the lumen of an introducer sheath.

FIG. 6E is an expanded view of the distal portion of the filter deliverysystem shown in FIG. 6D, illustrating the placement of the vessel filterhooks within the grooves on the inner surface of the spline cap.

FIG. 6F is a perspective view of one variation of a safety cap. Thesafety cap is designed for placement over the distal end of a deliverycatheter for securing the vessel filter loaded within the distal lumenof the delivery catheter during transport.

FIG. 6G is a cross-sectional view of the safety cap of FIG. 6F.

FIG. 6H illustrates one variation of an introducer sheath with itscorresponding dilator position within its lumen. The introducer sheathand the dilator are interlocked as a unit for placement over aguidewire.

FIG. 6I illustrates the introducer sheath of FIG. 6H with the dilatorremoved, and a delivery catheter loaded with a vessel filter is insertedin the lumen of the introducer sheath. The distal portion of thedelivery catheter is shown interlocked to the introducer sheath suchthat the dilator and the delivery catheter may be displaced within ablood vessel as a single unit when they are interlocked to each other.

FIG. 7A is a perspective view of another variation of a deliverycatheter. In this variation, six wirings are provided at the distal endof the catheter to center the delivery catheter within a vessel.

FIG. 7B is a side view of the delivery catheter of FIG. 6A.

FIG. 7C illustrates a vessel filter positioned within the lumen of adelivery catheter with distal end centering wirings. The deliverycatheter is shown positioned within the lumen of an introducer sheath.

FIG. 7D illustrates another variation of a centering mechanismcomprising a plurality of loops connected to the distal end of thecatheter.

FIG. 8A is a perspective view of another variation of a spline cap withsix slots for receiving filter hooks, and six holes for the placement ofcentering wirings.

FIG. 8B is a perspective view of the spline cap of FIG. 8A, shown at adifferent angle.

FIG. 8C is a frontal view of the spline cap of FIG. 8A. The spline capis shown from the distal end down its longitudinal axis.

FIG. 9A is a cross-sectional view of the spline cap of FIG. 8A.

FIG. 9B is a cross-sectional view of the spline cap of FIG. 9A, shownwith the spline cap rotated 30 degree along its longitudinal axis.

FIG. 10A is a side view illustrating one variation of a pusher-wirehaving a deployment jig attached to the distal end of the pusher-wire.The deployment jig is configured for loading and unloading the vesselfilter into the lumen of a deployment catheter.

FIG. 10B is a top view of the pusher-wire of FIG. 10A.

FIG. 10C is a perspective view of the pusher-wire of FIG. 10A.

FIG. 11 illustrates a pusher-wire extending from the lumen of a deliverycatheter. The deployment jig located at the distal end of thepusher-wires captured the filter sleeve of a vessel filter. The vesselfilter is shown in a compressed position.

FIG. 12 illustrates another variation of a pusher device. The pusherdevice comprises a receptacle attached to the pusher pad through a wire.The receptacle is configured with chambers to receive the hooks on thevessel filter.

FIG. 13 illustrates the pusher device of FIG. 12 placed within the lumenof a delivery catheter.

FIG. 14A illustrates the filter delivery system of FIG. 13 with a vesselfilter loaded on the pusher device. The delivery catheter and itscorresponding pusher device are placed within the lumen of an introducersheath.

FIG. 14B illustrates the partial release of the vessel filter of FIG.14A. The arms of the filter are shown in an expanded position, while thelegs with their corresponding hooks are still secured by the receptacleon the pusher device.

FIG. 15A is a side view of one variation of a filter hook receptacle.

FIG. 15B is a prospective view of the filter hook receptacle of FIG.15A.

FIG. 15C is a cross-sectional view of the filter hook receptacle of FIG.15A.

FIG. 15D is a frontal view of the filter hook receptacle of FIG. 15A.The filter hook receptacle is shown from its proximal end down itslongitudinal axis.

FIG. 16A is a prospective view of another variation of a filter hookreceptacle.

FIG. 16B is a frontal view of the filter hook receptacle of FIG. 16A.The filter hook receptacle is shown from its proximal end down itslongitudinal axis.

FIG. 17 illustrates another variation of a delivery catheter where aplurality of orifices are provided at the distal portion of the catheterfor receiving and separating the hooks from a vessel filter insertedinto the lumen of the catheter.

FIG. 18 illustrates another variation of a delivery catheter where aplurality of slots are provided at the distal end of the catheter forreceiving and separating the hooks from a vessel filter inserted intothe lumen of the catheter. As shown in FIG. 18, in this variation, theslots spanned across the thinness of the catheter wall.

FIG. 19 illustrates another variation of a vessel filter.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings, in which identical reference numbers refer to like elementsthrough out the different figures. The drawings, which are notnecessarily to scale, depict selected embodiments and are not intendedto limit the scope of the invention. The detailed descriptionillustrates by way of example, not by way of limitation, the principlesof the invention. This description will clearly enable one skilled inthe art to make and use the invention, and describes severalembodiments, adaptations, variations, alternatives and uses of theinvention, including what is presently believed to be the best mode ofcarrying out the invention.

Before describing the present invention, it is to be understood thatunless otherwise indicated, this invention need not be limited toapplications in humans. As one of ordinary skill in the art wouldappreciate, variations of the invention may be applied to other mammalsas well. Moreover, it should be understood that embodiments of thepresent invention may be applied in combination with various vesselfilters, guidewires, catheters, tubing introducers or other filterdeployment devices for implantation of a filter in a vessel within apatient's body.

A vena cava filter is used herein as an example application of thefilter deployment device to illustrate the various aspects of theinvention disclosed herein. In light of the disclosure herein, one ofordinary skill in the art would appreciate that variations of the filterdeployment device may be applicable for placement of filters in variousblood vessels, hollow body organs or elongated cavities in a human body.It is also contemplated that the vessel filter described herein may beimplemented for capturing particles other than blood clots.

It must also be noted that, as used in this specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, the term “a hook” is intended to mean a single hook or acombination of hooks, “a fluid” is intended to mean one or more fluids,or a mixture thereof. Furthermore, the words “proximal” and “distal”refer to directions closer to and away from, respectively, a physicianoperating the delivery catheter with the tip end (i.e., distal end)placed inside the patient's body. Thus, for example, the catheter endplaced in the vena cava of the patient would be the distal end of thecatheter, while the catheter end outside the patient's body would be theproximal end of the catheter.

Referring to FIG. 1, a delivery catheter 2 configured for securing avessel filter and placing the vessel filter to a desired location withina patient's vascular system is illustrated. In this variation, thecatheter 2 is configured with six grooves 4, 6, 8, 10, 12, 14, (e.g.,slots, notches, surface indentations, etc.) positioned on the innersurface 16 of the catheter 2 at the distal end 18 of the catheter. Thesix grooves 4, 6, 8, 10, 12, 14, are configured to receive six hooks 20,22, 24, 26, 28, 30 on a corresponding vessel filter 32. The grooves 4,6, 8, 10, 12, 14 are design to prevent the hooks 20, 22, 24, 26, 28, 30and their corresponding legs 34, 36, 38, 40, 42, 44 from entangling witheach other. In addition, because the grooves allow the hooks to remainin an expanded normal state while loaded in the catheter, the groovesmay also minimize stress on the hooks. The delivery catheter maycomprise a continuous piece of tubing with grooves etched into thedistal end thereof. Alternatively, the delivery catheter may compriseelongated flexible tubing with a spline cap configured with groovesattached to the distal end of the tubing, as will be described in moredetail below.

A vessel filter 32, such as the one shown in FIG. 2, may be compressedso that the expandable legs 34, 36, 38, 40, 42, 44 on the filter 32collapse toward a longitudinal axis 46 of the vessel filter 32. Thevessel filter 32 in the compressed state may be inserted into the distalend 18 of the delivery catheter 2 with the proximal end 48 (i.e., theend with the sleeve 50) going into the lumen 52 of the catheter 2 first.The legs 34, 36, 38, 40, 42, 44 of the vessel filter 32 may be adjustedsuch that when the filter 32 is completely inserted into the deliverycatheter 2, the hooks 20, 22, 24, 26, 28, 30 on the legs are placedwithin the corresponding grooves 4, 6, 8, 10, 12, 14 at the distal end18 of the delivery catheter. Preferably, the grooves are configured toreceive the hooks at the distal end of legs only, and not the length ofthe legs themselves. In an alternative design, the grooves may beconfigured with longer lengths and/or a deeper profiles such that theymay accommodate at least part of the elongated portion of the legs. Inaddition to separating the hooks and thus their corresponding legs, thegrooves may also prevent the filter from rotating within the lumen ofthe catheter.

In the particular variation of vessel filter shown in FIG. 2, the vesselfilter 32 comprises two sets of legs 34, 36, 38, 40, 42, 44, and 54, 56,58, 60, 62, 64 (e.g., flexible or semi-flexible wiring, etc.) extendingfrom a sleeve 50 in the radial direction towards the distal end 12 ofthe filter. The legs are configured with materials such that they may becollapsed toward a longitudinal axis 46 of the filter 32 for insertioninto a delivery catheter 2. A first set of six legs 54, 56, 58, 60, 62,64 when expanded, forms a first conical-shaped filter basket centered onthe longitudinal axis 46 of the vessel filter 2. A second set of sixlegs 34, 36, 38, 40, 42, 44, when expanded, forms a secondconical-shaped filter basket positioned distal to the first basket,which is also centered on the longitudinal axis 46 of the vessel filter2. Hooks 20, 22, 24, 26, 28, 30 are provided at the distal ends of thesecond set of legs 34, 36, 38, 40, 42, 44 for anchoring the distal endof the second set of legs into the walls of the vessel.

Although in the filter example discussed above, the plurality of legsforms two filter baskets along the longitudinal length of the device,one may configure the device with only one filter basket, oralternatively with three or more filter baskets. In addition, the devicemay be configured with three or more legs forming each basket, and isnot limited to the six-legged basket shown in FIG. 2. Also, as discussedabove, barb feet (e.g., hooks) may be provided on the distal end of eachleg. As one of ordinary skill in the art would appreciate, the preciselength and angle of the barb feet may be designed to provide secureattachment to the vessel wall without causing perforation or tearing.Moreover, hooks may be provided on all the distal legs or only on someof the distal legs. Hooks may also be provided on the proximal legs ifdesired. Furthermore, secondary struts may be provided forinterconnecting two or more of the radially expandable legs. Thesecondary struts may increase wiring density for each filter basket,which may in turn increase the filters capability to capture smallerparticles. In addition, the sleeve 50 may be comprised of abiocompatible metal, metal alloy, or polymeric material. The legs 34,36, 38, 40, 42, 44, 54, 56, 58, 60, 62, 64 may be comprised of a metal(e.g., stainless steel, titanium, etc.), metal alloy (e.g., titaniumalloy, Elgiloy, an alloy comprising Cobalt-Nickel-Chromium, etc.), shapememory material (e.g., Nitinol, shape memory alloyed, shape memorypolymer, etc.), or polymeric material (e.g., biocompatible plastics,etc.).

Referring to FIG. 3, a vessel filter 32 is placed within a deliverycatheter 2, which is slidably disposed in the lumen 66 of an introducersheath 68. The vessel filter 32 is located within the distal portion ofthe catheter 2. The wall of the delivery catheter 2 prevents the legs54, 60, 34, 40 of the vessel filter from expanding. The hooks 20, 26rest in their corresponding grooves 10, 4 at the distal end 18 of thedelivery catheter 2. As shown in FIG. 3, an optional ledge 70 isprovided in each of the grooves 10, 4. When the hook rests within thegroove, the ledge blocks the hook from moving in the proximal direction.As a result, the vessel filter 32 can not migrate in the proximaldirection (−Z) along the length of the catheter 2 lumen.

To deploy the vessel filter, a pusher-wire inserted inside the lumen ofthe delivery catheter proximal of the vessel filter may be utilized tounload the vessel filter. The pusher-wire may comprise a flexible wiringor a flexible rod with its distal end configured to contact the proximalend of the vessel filter. The pusher-wire may have a pusher pad attachedto its distal end. To deploy the vessel filter, one would insert theintroducer sheath into the circulatory system through methods well knownto one of ordinary skill in the art. The introducer sheath provides apathway for the physician to advance the delivery catheter loaded withthe vessel filter to the desired deployment location. One may thenadvance the distal tip of the delivery catheter out the distal openingof the introducer sheath. With the distal tip of the pusher-wirepositioned just proximal of the proximal end of the vessel filter, thephysician may retract both the introducer sheath and the deliverycatheter while simultaneously holding the pusher-wire in place to forcethe vessel filter out of the lumen of the delivery catheter. As theintroducer sheath and the delivery catheter are displaced in theproximal direction (−Z) relative to the vessel filter, the filter isdeployed into the blood vessel. As the filter slides out of the deliverycatheter's lumen, the legs of the vessel filter expand and engage thewall of the blood vessel. Because the hooks are separated by theircorresponding grooves, the hooks are prevented from interlocking withone another and a smooth deployment may be achieved.

In the variation shown in FIG. 4A, the vessel filter 32 is loaded withinthe lumen 52 of the delivery catheter 2, positioned such that the longlegs 34, 36, 38, 40, 42, 44, having hooks at their distal ends alignedwith the grooves 10, 8, 6, 4, 14, 12 of the delivery catheter 2, whereeach of the hooks rest within its corresponding groove. The short legs54, 56, 58, 60, 62, 64 rest directly on the inner lumen wall of thedelivery catheter 2. Although in this example six grooves are providedto support a filter with six hooks, one of ordinary skill in the arthaving the benefit of this disclosure would appreciate that othercombination of grooves (e.g., three, four, five, seven or more) may beimplemented to accommodate various filter designs. In addition, one ofordinary skill in the art would appreciate that the grooves may beconfigured to be various other geometric shapes. The spacing of thegroove distribution around the lumen opening may also vary depending onthe design of the vessel filter.

Furthermore, the groove may be configured to extend along thelongitudinal axis of the catheter. In the example shown in FIG. 4B, thedistal end 72 of the groove 74 is open to allow the hook 76 to easilyslide out of the distal end 18 of the delivery catheter 2. The proximalend 78 of the groove 74 is configured with a ledge 80 which mayinterface with the hook and prevent the vessel filter from migrating inthe proximal direction. It is preferable that the length of the groove“D2” along the longitudinal axis of the catheter is one-fourth of aninch or less; more preferably “D2” is one-eighth of an inch or less.Alternatively, one may design the length “D2” of the groove based on thelength of the hook “D1” along the longitudinal axis of its correspondingleg. Preferably, “D2” is equal or less than ten times the length of“D1”; more preferably “D2” is equal or less then four times the lengthof “D1”. In addition, it is preferable that the depth “D3” of thegrooves is equal or less than 0.06 inches; more preferably, the depth“D3” of the groove is equal to or less than 0.04 inches. The groove mayhave a constant depth along the circumferential direction.Alternatively, the groove may be designed with varying depths along thecircumferential direction. For example, the depth of the groove may bewider at the two edges, and narrower at the center, such that D4>D3, asshown in FIG. 4C. In one particular variation, the groove is designedwith a length D2=0.1 inches, the depth of the groove at the two edges D4are 0.014 inches, while the depth of the groove at the center D3 is0.013 inches, as shown in FIG. 4D. The particular vessel filter shown inFIG. 4D has a set of six identical hooks with each having a length D1 ofabout 0.025 inches.

Although in the above examples, each of the delivery catheters has a setof identical grooves, one of ordinary skill in the art having thebenefit of this disclosure would appreciate that the delivery cathetermay be designed with grooves of varying sizes. For example, the groovesmay have varying lengths, widths and depths to accommodate thecorresponding vessel filter to be inserted inside the lumen of thedelivery catheter. In one variation, the length of the legs on thevessel filter may be varied such that the positions of the hooks arestaggered along the longitudinal axis. The delivery catheter may bedesigned with grooves of varying lengths to accommodate this vesselfilter with staggered hooks. In another variation, the vessel filter mayhave hooks of varying sizes. The delivery catheter may be designed withgrooves of varying widths and depths to accommodate the variations inthe dimensions of the hooks.

In another variation, the delivery catheter comprises a spline cap 82attached to the distal end of a catheter. In one variation, as shown inFIG. 5A, the spline cap 82 comprises a piece of cylindrical metal with alumen extending from the distal end to the proximal end 86. A pluralityof grooves 88, 90, 92, 94, 96, 98 is placed on the inner circumferentialsurface at the distal end 84 of the spline cap 82 for receiving andseparating the hooks on the vessel filter. In this example, the lengthof the spline cap “L1” is 0.24 inches; the length of the groove “L2”along the longitudinal axis of the spline cap is 0.04 inches. In thisvariation, a ledge is provided at the proximal end of the groove toprevent proximal migration of the loaded vessel filter. The proximal endof the spline cap is configured with a C-bore 100. The distal end of thecatheter may be solvent-bond into the C-Bore 100 of the spline cap 2.The C-Bore has an inner radius “R1” of 0.114 inches. The grooves areevenly distributed in a circumferential manner around the lumen of thespline cap. As shown in FIG. 5B the grooves 88, 90 92, 94, 96, 98 aredisplaced in 60 degree increments. The width of the groove “L3” is 0.02inches; the inner diameter “R2” of the spline cap is 0.088 inches, theouter diameter “R3” of the spline cap is 0.124 inches, the depth of thegroove “L4” is 0.012 inches. In one particular variation, the deliverycatheter is designed to fit within an introducer sheath with a 10 Frenchinner diameter. Such a delivery catheter may be constructed by attachinga spline cap having a low profile design, as described above, to the tipof a catheter of corresponding size.

In addition, in this example, the dimensions of the grooves areconfigured to accommodate the hooks but not the length of the elongatedlegs. However, one of ordinary skill in the art having the benefit ofthe disclosure herein would appreciate the dimension of the grooves maybe modified to accommodate both the hooks and the corresponding legsthat connects to the hooks. For example, the length of the grooves maybe extended and the width widened to accommodate the legs. In addition,one may modify the depth of the grooves to accommodate the length of thelegs. In one variation, each groove may be configured with two sections,a proximal section configured to accommodate at least part of the leg,and a distal section configured to receive the corresponding hook (e.g.,the distal section may be deeper than the proximal section). Although inthe above example, the spline cap comprises a metallic material, one ofordinary skill in the art having the benefit of this disclosure wouldappreciate that the spline cap may comprise a polymeric material.

FIG. 6A illustrates another variation of a spline cap 102. In thisvariation, the proximal portion 104 of the spline cap 102 is configuredfor insertion into the lumen of a catheter to form a delivery catheter.Barbs 106, 108, 110, 112, 114, 116 and/or ribs may be provided on thecircumferential surface of the spline cap to improve contact between thespline cap 102 and the inner surface of the catheter. Adhesive may alsobe utilized to secure the spline cap in distal lumen of the catheter. Inthis example, as shown in FIG. 6B, the overall length “L5” of the splinecap is 0.4 inches; the length “L7” of each of the groove is 0.1 inches;the length “L8” of each of the barb is 0.04 inches; the outer diameter“R4” at the proximal end is 0.98 inches; the diameter “R5” at the edgeof each of the barb is 0.104 inches. FIG. 6C is a frontal view of thespline cap 102 showing the six grooves 118, 120, 122, 124, 126, 128evenly distributed around the lumen 130 in 60 degree increments. Theouter diameter “R6” at the distal end 132 of the spline cap is 0.1235inches, and the inner diameter “R7” is 0.088 inches. The spline cap 102may be manufacture with sharp edges 134 on the barbs, such that thespline cap 102 may be embedded into the catheter and be securelymaintained within the distal end of the catheter.

FIG. 6D illustrates a vessel filter 136 positioned within the lumen 138of a delivery catheter 140 for deployment. As shown, both the legs 142and the arms 144 of the vessel filter 136 are in a contracted position.In this example, the delivery catheter 140 comprises a catheter 146 withthe spline cap 102 shown in FIG. 6A, inserted within the distal end 148of the catheter 146. A pusher-wire 150 is also placed within the lumen138 of the delivery catheter 140 immediately proximal to the sleeve 152(i.e. head-end) of the vessel filter 136. The distal end of thepusher-wire has a pusher pad 154 to improve contact between thepusher-wire 150 and the vessel filter 136. The delivery catheter 140 isshown slidably positioned within the lumen of an introducer sheath 156.FIG. 6E is an expanded view illustrating the placement of the hooks 158within the corresponding grooves 160 on the inner wall 162 of the splinecap 102. Each hook 158 is placed within one of the six grooves 160 thatare distributed around the distal lumen opening 164.

FIG. 6F illustrates an optional cap 166 or cover for securing the vesselfilter after the vessel filter has been loaded within the lumen of thedelivery catheter. The cap is configured for placement over the distalend of the delivery catheter after the vessel filter has been insertedinto the distal end of the delivery catheter. The lumen 168 of the cap166 is wide enough to receive the distal portion of a delivery catheter.The inner base of the cap 166 may be configured with a protrusion 170such that when the cap 166 is placed over the delivery catheter, theprotrusion 170 may advance into the distal lumen of the deliverycatheter. The protrusion 170 may engage the hooks to prevent the vesselfilter from sliding and may also keep the hooks in their correspondingslot. In this example, the length “L10” of the cap” is 0.44 inches; thelength “L12” of the inner protrusion is 0.06 inches; the width “L11” is0.28 inches; and the diameter “R8” at the proximal end is 0.19 inches.In one application, the vessel filter is loaded into the deliverycatheter at the manufacturing site before it is delivered to thehospital for implantation into a patient. A safety cap 166, such as oneshown in FIG. 6F may be placed over the distal end of the deliverycatheter to keep the filter in place and prevent movement of the vesselfilter during transport. When the surgeon is ready to implant the vesselfilter, the surgeon may then remove the safety cap and insert thedelivery catheter along with the loaded vessel filter into an introducersheath that has been inserted into the patient's blood vessel.

The vessel filter delivery device disclosed above may be utilized forimplantation of a vessel filter into various hollow body organsthroughout the human body. In a common application, the vessel filterdelivery device is inserted into the jugular vein at the patient's neckor the subclavian vein under the clavicle, for placement of a vesselfilter at the inferior vena cava. For example, the implantable vesselfilter is prepared by collapsing the legs of the filter and insertingthe proximal end (i.e., sleeve or head-end) of the filter into thedistal opening of the delivery device, and making sure that the each ofthe hooks are aligned with its corresponding grooves/cavities on theinner lumen surface at the distal end of the catheter. The compressedvessel filter is positioned with the filter hooks next to the distalopening of the delivery catheter and the proximal end of the vesselfilter aligned towards the proximal end of the delivery catheter. Thesurgeon first locates a suitable jugular or subclavian vein. An incisionis made to access the vein. A guidewire is inserted into the vein andadvanced towards the inferior vena cava. An introducer sheath togetherwith its tapered dilator is advanced over the guidewire, and the distalportion of the introducer sheath is advanced into the inferior venacava. The guidewire and the dilator are then removed, leaving theintroducer sheath with its tip in the inferior vena cava. Venacavavogramor other imaging techniques may be used to position the introducersheath for optimal placement of the vessel filter. The filter deliverydevice loaded with the vessel filter is then inserted into theintroducer sheath and advanced toward the inferior vena cava. Once thedelivery assembly is positioned for desired placement of the vesselfilter, the surgeon holds the pusher-wire in place while simultaneouslypulling the introducer sheath and the delivery catheter in a proximaldirection. The introducer sheath and the delivery catheter are retractedover the pusher-wire, exposing the vessel filter. The pusher pad at thedistal end of the pusher-wire forces the vessel filter to exit thefilter delivery device and allows the vessel filter's legs to expand andengage the vessel wall. The delivery assembly and the introducer sheathmay then be removed.

FIG. 6H illustrates one variation of an introducer sheath 172 anddilator 174 combination. The dilator 174 is slid into the introducersheath 172 by inserting the distal end 176 of the dilator 174 into theproximal opening of the introducer sheath 172. Once the dilator 174 isadvanced all the way into the introducer sheath 172, the dilator hub 178at the proximal end 180 of the dilator 182 tubing will engage the fluidinfusion hub 184 at the proximal end 186 of the introducer sheath 172.An optional interlocking mechanism 188 may be provided to connect thedilator hub 178 to the fluid infusion hub 184 on the introducer sheath172. The interlocking mechanism 188 may comprise a snap-on interface190. For example, the fluid infusion hub 184 on the introducer sheath172 may be configured with a groove/profile for receiving acorresponding protrusion 192 or raised profile on the dilator hub 178,such that the dilator hub 178 may be snapped onto the fluid infusion hub184 on the introducer sheath 172.

As shown in FIG. 6H, the dilator 174 and the introducer sheath 172 areinterlocked together and may be operated as a single unit. In thisexample, the overall length “L13” of the combined unit is 26.63 inches;the length “L14” of the dilator 174 measured from the base of the fluidinfusion hub to the tip 176 of the dilator is 24.43 inches; the length“L15” of the tapered tip portion of the dilator 174 is 0.26 inches; thelength “L16” of the introducer sheath 172 measured from the base of thefluid infusion hub to the tip 196 of the sheath is 21.66 inches; and thelength “L17” of the tapered distal portion of the introducer sheath is0.25 inches. Side ports 194 are provided along the length of the distalportion of the dilator such that fluid infused through the dilator 174may exit the side ports 194 and dilate the blood vessel. Thedilator/introducer sheath unit 210 may then be inserted over a guidewireinto the patient's circulatory system. Once the distal end 196 of theintroducer sheath 172 is placed at the desired location in the bloodvessel, the surgeon may disengage the dilator 174 from the introducersheath 172 and withdrawal the dilator 174 and the guidewire from thelumen of the introducer sheath 172.

With the lumen of the introducer sheath 172 freed of obstructions, thesurgeon may then insert a deliver catheter 198 loaded with a vesselfilter into the proximal opening on the introducer sheath 172, andadvance the delivery catheter 198 along the length of the introducersheath 172. Once the delivery catheter 198 is inserted all the way intothe introducer sheath 172, the fluid infusion hub 202 on the proximalend of the delivery catheter will abut the fluid infusion hub 184 on theproximal end 186 of the introducer sheath 192. An optional interlockingmechanism 180 may be provided to connect the two fluid infusion hubs184, 202 together, and thereby linking the delivery catheter 198 and theintroducer sheath 172 into a single operating unit. The deliverycatheter tubing 204 and the introducer sheath 172 may then be displacedover the pusher-wire 206 as a signal unit. The interlocking mechanism188 may comprise a snap-on interface. For example, the introducer sheath172 may be configured with a groove/profile for receiving acorresponding protrusion 208 or raised profile on the delivery catheter198, such that the fluid infusion hub 202 on the delivery catheter 198may be snapped onto the fluid infusion hub 184 on the introducer sheath172, as shown in FIG. 61.

FIG. 61 illustrates a delivery catheter 198 inserted inside the lumen ofthe introducer sheath 172, and the proximal end of the introducer sheath186 engages the fluid infusion hub 202 on the delivery catheter 198 andinterlocks the two devices together. Also shown in FIG. 6I, a vesselfilter 200 is loaded within the distal lumen of the delivery catheter198 and a pusher-wire 206 is positioned within the proximal lumen of thedelivery catheter 198. In this example, the overall length “L18” of thedelivery catheter/introducer sheath assembly 212 is 35.32 inches; thelength “L19” of the delivery catheter tubing 204 measured from the baseof the fluid infusion hub to the tip of the delivery catheter is 21.96inches; the length “L20” of the portion of the delivery catheter 198that protrudes from the distal end 196 of the introducer sheath 172 is0.29 inches; the length “L21” of the channel 216 in the delivery hubextension 218 that accommodates the sliding of the block-stop 220 is 3inches; the length “L22” measured form the distal end of the block-stop220 to the proximal end of the delivery hub extension is 0.3 inches; andlength “L23” of the safety clip 222, which is also the maximumdisplacement distance for the pusher-wire 206, is 2.95 inches.

In this example, a delivery hub extension 218 is provided to guide thedisplacement of the pusher-wire 206. A block-stop 220 which is fixedlyconnected to the pusher-wire 206 is positioned within a channel 216 inthe delivery hub extension housing 218. The block-stop 220 prevents theuser from over withdrawal of the pusher-wire 206. As shown in FIG. 61,when the pusher-wire 206 is fully displaced in the proximal direction,the block-stop 220 abuts the proximal wall of the delivery hub extension218 and prevents further withdrawal of the pusher-wire 206. Optionally,the block-stop 220 may be configured with a cross-sectional profile,such as square, that matches the inner surface of the delivery hubextension housing 218 to prevent the pusher-wire 206 from rotating. Thisanti-rotational mechanism may be particularly useful when a deploymentjig is implemented at the distal end 224 of the pusher-wire 206, sincethe rotation of the jig, which engages the vessel filter, may cause thelegs of the vessel filter 200 to become entangled with each other.However, in a design utilizing a pusher pad 226, such as the one shownin FIG. 6I, an anti-rotational mechanism is not necessary.

The safety clip 222 prevents the surgeon from prematurely deploying thedelivery filter 200 by preventing the pusher-wire 206 from displacing inthe distal direction. When the delivery catheter 198 is fully insertedinto the introducer sheath and successfully engages the introducersheath's interlocking mechanism 188, as shown in FIG. 61, the surgeonmay then remove the safety clip 222. Holding the handle 228 at theproximal end 230 of the pusher-wire 206 in place, the surgeon may thenretract the delivery catheter/introducer sheath assembly 212, causingthe delivery catheter tubing 204 and the introducer sheath 172 tosimultaneously displace in the proximal direction and allowing thevessel filter 200 to deploy. Once the vessel filter 200 is successfullydeployed, the surgeon may then withdrawal the deliverycatheter/introducer sheath assembly 212 from the patient's circulatorysystem. In the example shown in FIG. 61, the safety clip 222 comprises atab such that the surgeon may easily push the safety clip off 222 thepusher-wire 206. Alternatively, a loop may be provided on the safetyclip 222 so that the surgeon can easily pull the safety clip 222 off thepusher-wire 206. Instruction for removal of the safety clip 222 may beprovided on the safety clip in the form of lettering and/or graphicicon.

Referring to FIG. 7A, a delivery catheter 232 with a centering mechanism234 is illustrated. The centering mechanism 234 comprises a plurality offlexible elements 236 (e.g. wires, rods, etc.) configured around thedistal end 238 of the delivery catheter 232 such that the flexibleelements 236 flare outward from a longitudinal axis 240 of the catheter232, as shown in FIG. 7B. The flexible elements may comprise abiocompatible metal, metal alloyed, polymer, or a combination thereof.When the delivery catheter is deployed inside a blood vessel, theflexible elements 236 push against the wall of the blood vessel andcenter the distal tip 238 of the catheter 232 within the blood vessel.In the example shown in FIG. 7A, the delivery catheter 232 is alsoconfigured with an optional feature for separating the hooks of a vesselfilter to be loaded into the distal 238 end of the delivery catheter. Asshown, grooves 242 are provided at the distal end of the inner lumen forreceiving and separating the hooks.

FIG. 7C illustrates a vessel filter 246 loaded in the distal end 238 ofa delivery catheter 232. The delivery catheter 232 is slidably disposedwithin an introducer sheath 248. The wall of the introducer sheathcompresses the flexible elements 236 at the distal end of the deliverycatheter and allows the physician to advance the delivery catheter 232within the lumen 250 of the introducer sheath 248. When the introducersheath 248 is retracted from the distal end 238 of the delivery catheter232 and exposes the flexible elements 236, the flexible elements 236will flare outward. The distal end 252 of each of the flexible elements236 may then contact the vessel wall and pushed against the vessel wall.The collective action of all flexible elements 236 will center the tipof the delivery catheter 232 within the blood vessel. The physician maythen deploy the vessel filter 246 by either retracting the deliverycatheter 232 and the introducer sheath 248, thereby exposing the vesselfilter 246, or by pushing the vessel filter 246 out of the distal end238 of the delivery catheter 232 with a pusher-wire 254.

Referring to FIG. 7D, another variation of a centering mechanism isillustrated. In this variation, a plurality of loops 231, 233, 235, 237are connected to the distal end of a catheter 239. The loops maycomprise of metallic material, polymeric material, or a combinationthereof. In the expended state the loops 231, 233, 235, 237 expandoutwardly away from the longitudinal axis of the catheter 239. Thecatheter may be placed inside of an introducer sheath for deployment.The wall of the sheath forces the loops to collapse inward toward thelongitudinal axis. Optional grooves may be provided on the inner wall ofthe catheter 239 to separate the hooks on a vessel filter loaded withinthe catheter 239.

In one variation, the flexible elements 236 for centering the catheter232 is attached to the distal end 238 of a catheter 232 through a splinecap 260 serving as the interface. An example of a spline cap 260 withholes 262 for receiving the flexible elements 236 is shown in FIG.8A-8C. In this design, the spline cap 260 is configured with a lumen 264running from the distal end 266 of the spline cap 260 to the proximalend 268 of the spline cap 260, as shown in FIG. 8A. The proximal end 268of the spline cap is configured with a bore 270 to receive a catheter272, as shown in FIG. 8B. Six holes 262 are provided on the distal end266 of the spline cap 260 to receive six flexible elements 236, as shownin FIG. 8C. The flexible elements may comprise of six flexible metalwires, or six flexible polymeric rods, or a combination thereof. Sixoptional slots 274 are also built into the inner wall 276 of the splinecap 260 for receiving six corresponding hooks on a vessel filter 246.FIGS. 9A and 9B shows the cross-sectional view of the spline cap 260. Inthis variation, each of the holes 262 for receiving the flexibleelements 236 has a length “L24” of 0.138 inches, as shown in FIG. 9A.The diameter of the spline cap 260 at the distal end “R9” is 0.17inches; the diameter at the proximal end “R10” is 0.14 inches; thediameter of the lumen “R11” is 0.088 inches. The length “L25” of each ofthe grooves is 0.04. As shown in FIG. 9B, in this example, the ledge 278at the proximal end of each of the groove 274 is configured with aprofile configured to match the curvature of the hook. The curvedprofile at on the ledge 278 of the groove 274 may help maintain theshape of the distal portion of the hook and/or prevent fatigue of thematerial comprising the hook.

In another aspect of the invention, a pusher device 280 with anattachment 282 for interfacing with the proximal end 284 of a vesselfilter 286 is implemented for loading and unloading of the vessel filter286 from the delivery catheter 288. The pusher device 280 may comprise aflexible elongated body 290 (e.g., wire, rod, etc.) with a jig 292attached to the distal end of the flexible elongated body 290, as shownin FIG. 10A. In this example, the jig 292 comprises a base 294 wrappingaround the distal tip 296 of the pusher-wire 290, as shown in FIG. 10C.An elongated member 298 extends from the distal end 296 of thepusher-wire in the distal direction. At the distal end 300 of theelongated member, two prongs 302, 304 extend laterally and curve upwardfor engaging the neck 306 of a vessel filter 286. Referring back toFIGS. 10A and 10B, in this variation, the jig 292 has an overall length“L26” of 0.4 inches and an overall diameter “R12” of 0.072 inches; theelongated member 298 has a length “L27” of 0.25 inches and width “L28”of 0.03 inches; the height “L29” of each of the two prongs 302, 304 is0.023 inches. The two prongs 302, 304 may have a tapered or roundedatraumatic configuration to prevent the jig 292 form causing damages tothe inner wall of a blood vessel during deployment.

FIG. 11 illustrates a pusher-wire 290 with a deployment jig 292 at thedistal end, extending out the distal lumen of a delivery catheter 288 toengage a vessel filter 286. In this variation, the deployment jig 292 isdesigned with two lateral prongs 302, 304 which can be placed around theneck 306 of the vessel filter 286 and engages the sleeve 308 or the headof the vessel filter 286. The deployment jig 292 allows the user to pullon the vessel filter 286 and facilitate the loading of the vessel filter286 into the lumen of the delivery catheter 288. The deployment jig 292is also designed to release the vessel filter upon deployment byminimizing the surface contact between the vessel filter 286 and thedeployment jig 292. One of ordinary skill in the art having the benefitof the disclosure herein would appreciate that other gripping orinterlocking mechanism may also be implemented at the distal end of thepusher-wire as the deployment jig for engaging the proximal portion ofthe vessel filter.

Referring now to FIG. 12, another variation of a pusher-wire 310 isillustrated. In this design the pusher-wire comprises an elongatedflexible body 312 (e.g., wire, rod, etc.), a pusher pad 314 attached tothe distal end of the elongated flexible body 312 for applying a forceonto the proximal end 314 of the vessel filter 316, and an extensionwiring 318 connecting a receptacle 320 to the pusher pad 314. Thereceptacle 320 is configured to receive the hooks on the legs of thevessel filter 316 and to keep the hooks separated from each other, suchthat the legs of the filter will not be entangled with each other.Preferably, the connection between the extension wiring 318 and thepusher pad 314 is offset from the longitudinal axis of the pusher-wire310 such that it does not interfere with the placement of the vesselfilter 316 immediately distal 322 of the pusher pad 314. The extensionwire may comprise Nitinol.

The pusher-wire 310 may be placed inside of a catheter 324 to form avessel filter delivery device 326 as shown in FIG. 13. In this example,the receptacle 320 is configured with a plurality of holes 326, each ofwhich is designed to receive the distal end of a filter leg. The distalend of each of the legs may have a hook. The holes 326 may be largeenough to accommodate the hooks in their expanded normal state (i.e.,curved). However, it is preferable that the hooks comprise of shapememory alloy and are straightened before they are inserted into theircorresponding holes 326 in the receptacle 320. To load a vessel filter316 into the delivery device 326, the user may advance the distalportion of the pusher-wire 310 out of the distal lumen opening 328 ofthe delivery catheter 324. The vessel filter 316 is placed between thepusher pad 314 and the receptacle 320, and the legs 330 of the vesselfilter 316 are inserted into the corresponding holes 326 on thereceptacle 320. The user may pull on the proximal end of the pusher-wire310, which extends from the proximal end of the delivery catheter 324,and drawn the distal portion of the pusher-wire 310 and the loadedvessel filter 316 into the lumen of the catheter 324.

The vessel filter delivery device 326 loaded with the vessel filter 316may be inserted into an introducer sheath 332 that has been positionedwithin the circulatory system of a patient through methods that are wellknown to one of ordinary skill in the art. The vessel delivery device326 is advanced along the length of the introducer sheath 332 until thedistal end 334 of the delivery catheter 324 protrudes from theintroducer sheath's 332 proximal lumen opening. FIG. 14A illustrates adelivery catheter 324 with a pusher-wire 310 having a vessel filter 316loaded on the receptacle 320; the delivery catheter 324 being slidablydisposed within the lumen of the introducer sheath 332.

To deploy the vessel filter 316 the user may retract the deliverycatheter 324 and the introducer sheath 322 at the same time to exposethe distal portion of the pusher-wire 310 and the vessel filter 316. Thearms 336 on the vessel filter 316 expand and engage the wall of theblood vessel, as shown in FIG. 14B. The user may then advance thepusher-wire 310 in the distal direction and allow the legs 330 of thevessel filter 316 to slide out of the receptacle 320 at the distal endof the pusher-wire 310. The legs 330 expand and the hooks at the distalend of the legs 330 are embedded into the wall of the blood vessel. Withthe arms 336 and the legs 330 of the vessel filter 316 in the expandedpositions, the receptacle 320 at the distal end of the pusher-wire 310may be retrieved by pulling on the pusher-wire 310 and allowing thereceptacle 320 to slide through one of the gaps between the expandedlegs 330 and arms 336. The distal portion of the pusher-wire 310 alongwith its receptacle 320 can then be retracted into the lumen of thedelivery catheter 324. The delivery catheter 324 and its introducersheath 332 may then be removed from the body of the patient.

Alternatively, the compressed vessel legs 330 may have enough tensionsuch that once the delivery catheter and the introducer sheath areretraced, as shown in FIG. 14B, the legs 14 will pop out of thereceptacle. The holes on the receptacle and/or the hooks on the legs maybe configured to facilitate the legs from exiting the receptacle whenthey are not compressed by the delivery catheter. In another variation,the hooks may comprise of Nitinol wires that are straightened beforethey are inserted into the holes on the receptacle. These straightenedhooks may allow the legs of the vessel filter to disengage from thereceptacle more easily. Once the legs are deployed, the patient's innerbody temperature will force the straitened hooks to convert back intoits original hook-shape and engage the inner wall of the blood vessel.

In another design, a second wiring having a jig or attachment mechanismat the distal end of the wiring may be placed within the deliverycatheter along with the pusher-wire. The pusher pad 314 may have a sidechannel to allow the second wiring to pass-through. The jig at thedistal end of the second wiring may engage the vessel filter sleeve. Thedelivery catheter and the introducer sheath are first partiallywithdrawn to expose the receptacle. Holding the second wiring in placeto secure the filter in position, the pusher pad may then be advanced topush the receptacle forward through the extension wiring. As theconsequence, the hooks at the distal end of the legs disengage from thereceptacle and expand outward. The delivery catheter and the introducersheath may then be completely retracted to expose the entire vesselfilter. The jig on the second wiring is then detached from the vesselfilter, and the second wiring along with the pusher-wire are retracedinto the lumen of the delivery catheter. With the vessel filterdeployed, the delivery catheter and the introducer sheath, along withthe pusher-wire and the second wiring, may then be removed from thepatient's body.

Alternatively, the second wiring, which engages the sleeve of the vesselfilter, along with the pusher pad may be hold in place while theoperator completely retracts the delivery catheter and the introducersheath to expose the entire vessel filter. The second wiring may then beutilized to pull vessel filter proximally and slide the hooks out of thereceptacle. Once the vessel filter is deployed, the second wiring andthe pusher-wire with the receptacle may then be retraced into the lumenof the delivery catheter. The operator may then remove the deliverycatheter and the introducer sheath, along with the pusher-wire and thesecond wiring, from the patient's body. One of ordinary skill in the arthaving the benefit of this disclosure would appreciate that othervariations of mechanisms may also be configured to disengage the legs ofthe vessel filter from the receptacle.

FIG. 15A illustrates one variation of a filter hook/leg receptacle 320.In this variation, the receptacle comprises a spline 338 with aplurality of orifices 340 for receiving the hooks. The proximal portion342 of the receptacle 320 is configured with a cone-shaped profile 344.The cone-shaped profile may facilitate the retrieval of the receptacle320 after the filter has been deployed by allowing the receptacle 320 topass between the legs of the deployed filter with limited obstruction. Aplurality of orifices 340 is provided on the cone-shaped profile 344 toreceive the hooks and/or legs of the vessel filter. The cone-shapedprofile 344 may also minimize obstruction and allow for easy insertionand smooth deployment of the legs. Preferably, the receptacle 320 has acircumferential outer surface 346 that matches or approximates the innerlumen of the delivery catheter, as shown in FIG. 15B, which may preventkinking of the catheter and facilitate smooth advancement of thepusher-wire within the lumen of the catheter.

FIG. 15C is a cross-sectional view of this particular receptacle 320. Inthis example, the outer diameter of the receptacle 320 is 0.08 inches;the length of the receptacle “L30” is 0.380 inches; the base of thereceptacle has a length “L31” of 0.147 inches; the depth “L32” of eachof the holes 340 measure from the proximal end 348 of the receptacle 320is 0.305 inches. To accommodate a filter with six hooks, six holes 340are evenly distributed around a center opening 350, as shown in FIG.15D. The center opening 350 is configured for receiving the distal endof the extension wire. The extension wire may be bonded into the centeropening 350 of the receptacle 320. The spline 338 may comprise a metal,a metal alloy, or a polymeric material. The extension wire 318 may be aNitinol wire that is 0.013 inches in diameter. As shown in FIG. 12, thepusher pad 314 may also be configured with a cone-shaped proximalprofile 352, and a circumferential surface 354 matching or approximatingthe inner lumen of the delivery catheter 324. This may allow the pusherpad 314 to keep the extension wire connection 356 away from the centerof the catheter to allow smoother deployment of the vessel filter 316.The pusher pad 314 may be of various shapes and comprise variousmaterials (e.g., electrometric materials, metal, metal alloys, polymers,etc.) that are well know to one of ordinary skill in the art. One ofordinary skill in the art having the benefit of this disclosure wouldalso appreciate that the receptacle 320 may adapt various othergeometric shapes and still serve essentially the same function ofkeeping hooks on the legs separated from each other.

In another example, the receptacle is made of a spline 358 with anorifice 360 surrounding a post 362, as shown in FIG. 16A. The proximalend 364 of the post 362 can be connected to an extension wire on thepusher device. The inner circumferential surface of the spline 358 isembedded with a series of grooves 366 for separating the hooks at thedistal ends of the legs, as shown in FIG. 16B.

In FIG. 17, another variation of a delivery catheter 3 is illustrated.In this configuration, a plurality of orifices 5 are provided at thedistal portion of the delivery catheter for receiving and separatinghooks on a vessel filter loaded within the lumen of the deliverycatheter. The orifices 5 may be placed close to the distal end 7 of thecatheter 3. In one example, the orifices 5 are placed within 2 mm fromthe distal end 7 of the catheter 3.

In one exemplary application, the vessel filter in inserted into thecatheter by compressing its legs and corresponding arms, if any. Thedelivery catheter may be configured with six orifices for receivinghooks from a six legged filter with a hook located at the distal end ofeach of the legs. The vessel filter may be loaded from either distal orproximal end of the delivery catheter depending on the particularcatheter design. For example, one may load the vessel filter from thedistal end of the catheter by first inserting the proximal end (i.e.,the sleeve of the vessel filter) into the distal lumen of the catheter.As the filter is completely advanced into the lumen of the catheter, thehooks on each of the legs will pop into the corresponding orifice on thedelivery catheter. If the hooks are long enough, the hooks may passthrough the orifices and protrude from the orifices' outer openings onthe outer circumferential surface of the delivery catheter. As thedelivery catheter with the loaded vessel filter is inserted into theproximal end of an introducer sheath, the protruding portion of thehooks will be forced back into the orifices. As the delivery catheter,along with the loaded vessel filter, is advanced towards the distal endof the introducer sheath, the hooks stays in their correspondingorifices and glides along the inner lumen wall of the introducer sheath.A pusher-wire with a pusher pad may be positioned within the lumen ofthe delivery catheter to keep the load vessel filter at the distalportion of the delivery catheter, as the delivery catheter is beingdisplaced within the introducer sheath.

Once the delivery catheter and the corresponding introducer sheath isproperly positioned within the blood vessel, the operator may thendeploy the vessel filter by holding the pusher-wire in place, whilesimultaneously withdraw the delivery catheter and the correspondingintroducer sheath. As the delivery catheter is withdrawn, the hooks onthe vessel filter legs will be forced out of their correspondingorifices in the delivery catheter. The inner edge of each of theorifices maybe tapered on the distal side, which is closer to the distalend of the catheter, to facilitate the filter hooks from sliding out ofthe orifices when the delivery catheter is retracted. Once the deliverycatheter and the corresponding introducer sheath are fully retracted,the legs and/or arms on the exposed delivery catheter may then expandand engage the inner wall of the blood vessel.

In FIG. 18, another variation of a delivery catheter 9 is shown. In thisconfiguration, a plurality of slots 11 are provided at the distal end 13of a catheter 9 for receiving and separating hooks on a vessel filterloaded within the lumen of the delivery catheter. As shown in FIG. 18,each of the slots spans across the thickness of the catheter wall, andopens toward the distal end 13 of the catheter. In one variation, thebase 15 of each of the slots comprises a flat surface, as shown in FIG.18. In another variation the base each of the slots has a rounded orotherwise curved profile. In the variation shown in FIG. 18, the slotsare configured to receive a vessel filter with six equal length legs.However, if the legs of the vessel filter have varying lengths, thelength of the slots along the longitudinal axis of the catheter may alsobe varied accordingly to accommodate the various vessel filter legs.

Referring now to FIG. 19, another example of an implantable vesselfilter 370, which may be deployed by the filter delivery devicedescribed above, is illustrated. In this variation, the vessel filter ismade of elongated wires, and the wires are held together at the filter'sproximal end by a hub 372 (e.g., sleeve) where they are plasma weldedtogether to the hub or otherwise joined. In the low temperaturemartensitic phase of wires made of thermal shape memory material (e.g.,Nitinol alloy), the sets of wires can be straightened and held in astraight form that can pass through a length of fine plastic tubing withan internal diameter of approximately 2 mm (e.g., 8 French catheter). Inits high temperature austenitic form, the vessel filter 370 recovers apreformed filtering shape as illustrated by FIG. 19. Similarly, wires ofspring metal can be straightened and compressed within a catheter ortube and will diverge into the filter shape of FIG. 19 when the tube isremoved. In its normal expanded configuration or preformed filteringshape, the vessel filter 370 comprises a double filter, having a firstproximally positioned basket section 374 and a second distally disposedfilter basket section 376. The two filter basket sections provideperipheral portions which can both engage the inner wall of a bodyvessel at two longitudinally spaced locations, and the two filter basketsections are generally symmetrical about a longitudinal axis passingthrough the hub 372. On the other hand, the first filter basket section374, which may act as a centering unit, may not always touch the vesselwall on all sides.

The first filter basket section 374 is formed from short lengths ofwire, which form legs 378 extending angularly, outwardly and thendownwardly away from the hub 372 and toward the distal end 380 of thevessel filter 370. Each leg 378 has a first leg section 382, whichextends angularly outwardly from the hub 372 to a transition section384, and an outer leg section 386, which extends angularly from thetransition section 384 toward the distal direction of the filter. Theouter leg sections 386 are substantially straight lengths with ends thatlie on a circle at their maximum divergence and engage the wall of avessel at a slight angle (preferably within a range of from ten toforty-five degrees) to center the hub 372 within the vessel. For afilter which is to be removed by grasping the hub 372, it may beimportant for the hub to be centered. The filter may be configured withsix wires 378 of equal length extending radially outward from the hub372 and circumferentially spaced, such as, for example, by sixty degreesof arc.

The second filter basket section 376 is the primary filter and caninclude up to twelve circumferentially spaced straight wires 388 formingdownwardly extending legs which tilt outwardly of the longitudinal axisof the filter 370 from the hub 372. A filter with a six wireconfiguration is discussed in this example, and the wires are of equallength. Alternatively, the length of the wiring may be staggered. Thewires 388 are preferably much longer than the wires 378, and have distaltip sections which are uniquely formed, outwardly oriented hooks 390which lie on a circle at the maximum divergence of the wires 388. Theremay be from three to twelve wires 388 formed with hooks 390, and in someinstances, the wire legs 378 may include similarly formed hooks at thefree ends thereof. The wires 388, in their expanded configuration ofFIG. 17, are at a slight angle to the vessel wall, preferably within arange of from ten to forty-five degrees, while the hooks 390 penetratethe vessel wall to anchor the filter against movement. The wires 388 areradially offset relative to the wires 90 and may be positioned halfwaybetween the wires 378 and also may be circumferentially spaced by sixtydegrees of arc. Thus, the combined filter basket sections 374 and 376can provide a wire positioned at every thirty degrees of arc at themaximum divergence of the filter sections. The filter section 376 formsa concave filter basket opening toward the distal end of the filter 370,while the filter section 374 forms a concave filter proximal of thefilter section 376.

Furthermore, the hooks 390 on the distal legs may be further configuredsuch that withdrawal force to which the hook is subjected will causeflexure in the juncture sections 392 so that the hook extends in thedistal direction of the filter to a position parallel or semi-parallelwith the axis of the leg 388. For example, the juncture section 392 mayhave considerably reduced cross-section relative to the cross-section ofthe leg 388 and the remainder of the hook 390 so that the stress exertedby the withdrawal tension may force it to bend outward. With the hook sostraightened, it can be withdrawn without tearing the vessel wall,leaving only a small puncture. In an alternative design, the entire hook390 can be formed with a cross-section throughout its length, which isless than that of the leg 388. This may result in straightening of thehook over its entire length in response to a withdrawal force. Suchelasticity in the hook structure may prevent the hook from tearing thevessel wall during withdrawal.

In addition, a hook or attachment interface may be provided at theproximal end of the hub to allow the operator to manipulate the vesselfilter through an elongated wire with a matching interface for engagingthe hook or the attachment interface. For example, a hook positioned atthe proximal end of the hub 372 may facilitate the removal of the vesselfilter. The operator may engage the hook with and elongated wire andhold the vessel in place while simultaneously advance a catheter overthe implanted vessel filter. The catheter forces the legs on the vesselfilter to collapse and slide into the lumen of the catheter. Once thevessel filter is inside the catheter the catheter, along with theretracted vessel filter, may then be removed from the patient's body.

This invention has been described and specific examples of the inventionhave been portrayed. While the invention has been described in terms ofparticular variations and illustrative figures, those of ordinary skillin the art will recognize that the invention is not limited to thevariations or figures described. In addition, where methods and stepsdescribed above indicate certain events occurring in certain order,those of ordinary skill in the art will recognize that the ordering ofcertain steps may be modified and that such modifications are inaccordance with the variations of the invention. Additionally, certainof the steps may be performed concurrently in a parallel process whenpossible, as well as performed sequentially as described above.Therefore, to the extent there are variations of the invention, whichare within the spirit of the disclosure or equivalent to the inventionsfound in the claims, it is the intent that this patent will cover thosevariations as well. Finally, all publications and patent applicationscited in this specification are herein incorporated by reference intheir entirety as if each individual publication or patent applicationwere specifically and individually put forth herein.

All measurements disclosed herein are at standard temperature andpressure, at sea level on Earth, unless indicated otherwise. Allmaterials used or intended to be used in a human being arebiocompatible, unless indicated otherwise.

The foregoing embodiments are presented by way of example only; thescope of the present invention is to be limited only by the followingclaims.

The invention claimed is:
 1. A vessel filter assembly, comprising: a) ahead; b) a plurality of elongated legs extending distally from saidhead; c) said plurality of elongated legs being configured to expandradially from an initial stored position to an expanded position; d)each of said plurality of legs having a hook located at a distal endthereof such that when said legs are moved to the expanded position thehooks engage an inner wall of the vessel, each hook having a hook freeend; e) an elongated catheter having a central, longitudinal axis andincluding an inner surface surrounding a lumen that extends from aproximal catheter end to a distal catheter end, the lumen beingconfigured to receive said vessel filter and maintain said vessel filterin a first compressed configuration that defines the stored position; f)a plurality of grooves being provided on the distal end of the catheterand communicating with the inner surface, said grooves beingcircumferentially spaced apart and configured for receiving said hooks;g) a transverse surface that transversely intersects each grooveproximally of said groove; h) wherein in the first compressed, storedposition, the hooks engage the catheter wall at said grooves to preventsaid plurality of legs from entangling with each other; i) wherein inthe first compressed, stored position, each hook free end engages a saidtransverse surface; and j) a filter delivery portion comprising adeployment jig located within the distal end of the elongated flexibletube and configured to connect with said vessel filter.
 2. The vesselfilter assembly according to claim 1, wherein the filter deliveryportion further comprises a rod connected to the deployment jig andslidably positioned within said elongated catheter for applying pressurewhen said vessel filter is to be moved from the stored position to adeployed position exiting from the distal end of said elongatedcatheter.
 3. The vessel filter assembly according to claim 2, whereinsaid vessel filter portion further comprises a plurality of armsextending distally from said head, wherein said plurality of arms areconfigured to expand radially from a longitudinal axis to form a secondfilter in an expanded position.
 4. The vessel filter assembly accordingto claim 3, wherein said arms are compressed by an inner wall of saidcatheter, and wherein said arms do not engage said plurality of grooveswhen said vessel filter is positioned within the lumen of said catheter.5. The vessel filter assembly according to claim 2, wherein a lengthalong the longitudinal axis of said catheter for each of said grooves isapproximately the length of said hooks along the longitudinal axis ofeach of said hook's corresponding leg.
 6. The vessel filter assemblyaccording to claim 1, wherein said filter is conically shaped.
 7. Thevessel filter assembly according to claim 1, wherein said grooves areconfigured to prevent the vessel filter from sliding proximally alongthe lumen of the catheter once said hooks are placed within saidgrooves.
 8. The vessel filter assembly according to claim 7, whereineach of said grooves is configured with a distal end opening at a distaltip of said elongated catheter to allow said hooks to slide out of saidgrooves, and wherein a proximal end of each of said grooves includessaid transverse surface for blocking said hooks and preventing saidvessel filter from migrating in the proximal direction along the lengthof the catheter.
 9. The vessel filter assembly according to claim 1,wherein each of said grooves is configured with a distal end opening ata distal tip of said elongated catheter to allow said hooks to slide outof said grooves, and wherein a proximal end of each of said groovesincludes said transverse surface for blocking said hooks and preventingsaid vessel filter from migrating in the proximal direction along thelength of the catheter.
 10. The vessel filter assembly according toclaim 1, wherein said grooves are configured such that said groovesprevent said vessel filter from sliding proximally along the lumen ofthe catheter once said hooks are placed within said grooves.
 11. Thevessel filter assembly according to claim 1, wherein said elongatedcatheter comprises a flexible tubing and a spline cap attached to adistal end of said tubing, said spline cap being configured with saidplurality of grooves at the distal end thereof, said grooves beingpositioned on an inner wall surrounding a lumen of said spline cap, andsaid grooves being configured to receive said hooks and to prevent saidplurality of legs from entangling with each other.
 12. The vessel filterassembly according to claim 11, wherein said grooves are configured toprevent said vessel filter from sliding proximally along the lumen ofthe catheter once said hooks are placed within said grooves.
 13. Thevessel filter assembly according to claim 11, wherein each of saidgrooves is configured with a distal end opening at the distal end ofsaid spline cap to allow said hook to slide out of said groove, andwherein a proximal end of each of said grooves includes said transversesurface for blocking said hook and preventing said vessel filter frommigrating in the proximal direction along a length of said flexibletubing.
 14. The vessel filter assembly according to claim 1, furthercomprising a filter delivery portion that comprises a sheath slidablydisposed around said elongated catheter.
 15. The vessel filter assemblyaccording to claim 1, wherein the radially extending transverse surfaceis generally perpendicular to the central, longitudinal tube axis. 16.The vessel filter assembly according to claim 1, wherein the jig has arecess that is receptive of the filter head.
 17. A vessel filterdelivery device for implanting an expandable vessel filter in a hollowbody organ in a human, comprising: a) an elongated flexible tube havingproximal and distal tube ends, an outer surface, an innercircumferential surface, a tube lumen extending from the proximal tubeend to the distal tube end; b) an expandable filter contained withinsaid tube lumen in a first, stored position, said filter including aplurality of filter legs, each leg having a distal hook with a hook freeend; c) a plurality of slots positioned at said distal end of the tubeand each slot communicating with the inner circumferential surfacethereof and tube lumen; d) wherein in said stored position, each of saidslots being configured to receive one of a plurality of said hooks onsaid expandable vessel filter; e) a distal end of said slots opening atthe tube distal end to allow said hooks to move distally of the tubelumen; f) a proximal end of each said slot including a radiallyextending ledge to prevent the vessel filter from migrating towards saidproximal end of said tube, wherein each hook free end engages a saidradially extending ledge in the stored position; and g) a jig movablewithin the distal tube end of the elongated flexible tube configured toconnect with said vessel filter to prevent the vessel filter fromjumping out of the distal end of the delivery device.
 18. The vesselfilter delivery device according to claim 17, further comprising anelongated flexible wire connected to the jig and slidably disposedwithin the lumen of said elongated flexible tube, wherein a distal endof said elongated flexible wire is configured to apply a force on saidvessel filter to deploy said vessel filter from the lumen of said tube.19. The vessel filter delivery device according to claim 18, whereinsaid vessel filter forms a conical shape in an expanded state, andwherein said hooks are discharged from and spaced from the distal end ofsaid tube.
 20. The vessel filter delivery device according to claim 18,further comprising an introducer sheath, wherein a lumen in saidintroducer sheath is configured to slidably receive said elongatedflexible tube, the introducer sheath comprising an interlockingmechanism for temporarily securing said elongated flexible tube withinthe lumen of said introducer sheath such that the introducer sheath andthe elongated tubing can be displaced inside a blood vessel as a singleunit.
 21. The vessel filter delivery device according to claim 17,further comprising a plurality of flexible elements including first andsecond ends, each of said flexible elements being attached to the distalend of said elongated flexible tube at the first end of said flexibleelement, the second end of said flexible element extending distally awayfrom the distal end of said elongated flexible tube and outwardly awayfrom a longitudinal axis of said elongated flexible tube.
 22. A vesselfilter delivery system, comprising: a) an elongated flexible tube havinga central, longitudinal axis, proximal and distal ends, and a tube wallwith an outer surface and an inner surface surrounding a tube lumen thatextends from the proximal end to the distal end; b) an expandable vesselfilter stored within the tube lumen in a compressed state, the filterincluding a head and multiple legs extending distally of the head, atleast some legs having a distal hook, each distal hook having a hookfree end; c) wherein the filter is movable between the compressed statewherein the filter is contained in the tube lumen and an expanded statewherein the filter is positioned distally of the distal end of theelongated flexible tube; d) the tube wall including a plurality of slotsthat each communicate with the distal end of the flexible tube, whereinthe slots are circumferentially spaced apart about the tube wall innersurface and lumen, the slots extending longitudinally along the tubewall inner surface, each slot terminating proximally at a radiallyextending ledge; e) wherein in said compressed state each of the slotsreceiving at least a portion of one of said distal hooks of one of thevessel filter legs, wherein the hook free end of each leg engages theledge to prevent the vessel filter from migrating beyond the ledge in aproximal direction; f) a pusher that engages the filter head proximallyand opposite the hooks, wherein the pusher is movable within the tubelumen from a proximal position to a distal position which proximal todistal movement of the pusher enables discharge of the filter from thetube and to the expanded state, wherein the hooks exit the tube beforethe head exits the tube; and g) a deployment jig located at the distalend of the pusher and configured to connect with said vessel filter. 23.The vessel filter delivery system according to claim 22, wherein theradially extending ledge is generally perpendicular to the central,longitudinal tube axis.
 24. The vessel filter assembly according toclaim 22, wherein the jig has a recess that is receptive of the filterhead.